Multi and interdisciplinary method to identify the true capacity of concrete bridges (TruBridges)

Enhancing bridge sustainability

Goal

The project aims to enhance bridge sustainability by reducing unnecessary strengthening or replacement costs through more accurate predictions of capacity and remaining service life. A key aspect of assessing bridge performance is evaluating redundancy—the ability to redistribute loads after component loss—and robustness, which ensures continued load-bearing without excessive damage.

Redundancy and robustness are evaluated using three approaches:

• deterministic (single scenario),
• reliability-based (probabilistic variations), and
• risk-based (including failure consequences).

The project will develop a framework in which experimental testing, finite element (FE) modelling, reliability analysis and risk assessment are combined to improve infrastructure management and maintenance decisions.

Project status and results

A framework has been built considering risk and reliability concepts to consider uncertainties and consequences of failure when assessing existing bridges' capacity. The framework includes an advanced metamodel-based reliability methodology for cases where the computational cost must be reduced. A FE model of a railway bridge based on the Lautajokki bridge, a structure tested in 1996 at Luleå University of Technology, has been developed.

This model and the framework will be further calibrated, updated, and evaluated with the experimental data obtained by testing real scale trough bridges under laboratory conditions. These bridges were cast using the geometry of the Lautajokki, as it is close to the average geometry of trough bridges in Sweden.